Advanced Monolithic Systems

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Amberly Cannon
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1 Advanced Monolithic Systems FEATURES 5V Version Available* Output Current of 1mA Very Low Quiescent Current Reverse Battery Protection Input-output Differential less than.6v Short Circuit protection Internal Thermal Overload Protection 1mA LOW DROPOUT VOLTAGE REGULATOR RoHS compliant APPLICATIONS Battery Powered Systems Portable Consumer Equipment Cordless Telephones Portable (Notebook) Computers Portable Instrumentation Radio Control Systems Personal Communication Equipment Toys Low Voltage Systems GENERAL DESCRIPTION The series consists of positive fixed voltage regulators ideally suited for use in battery-powered systems. These devices feature very low quiescent current of 1mA or less when supplying 1mA loads. This unique characteristic and the extremely low input -output differential required for proper regulation (.2V for output currents of 1mA) make the ideal to use for standby power systems. Like other regulators the series also includes internal current limiting, thermal shutdown, and is able to withstand temporary power-up with mirror-image insertion. The is offered in the 3-pin TO-92 package and SOT-89 package. ORDERG FORMATION P CONNECTIONS PACKAGE TYPE OPER. TEMP TO-92 SOT-89 RANGE N-X L-X D X =5V *For additional available fixed voltages contact factory TO-92 Plastic Package (N) SOT-89 Package (L) OUTPUT PUT GND PUT GND OUTPUT Bottom View Top View Advanced Monolithic Systems, Inc. Phone (925) Fax (925)

2 ABSOLUTE MAXIMUM RATGS (Note 1) Input Voltage 18V Maximum Junction Temperature 125 C Operating Voltage Range 2.5V to 16V Storage Temperature -65 C to 15 C Load Current 15mA Lead Temperature (Soldering 25 sec) 265 C Internal Power Dissipation Internally Limited ESD 2V ELECTRICAL CHARACTERISTICS Electrical Characteristics at T J =25 C, C2 = 1µF unless otherwise specified. PARAMETER CONDITIONS (Note 2) Min. -X Typ. Output Voltage V = V OUT 3V -3 3 % Line Regulation V = V OUT 3V to 14V 2 3 mv Load Regulation 5mA I 1 ma 15 6 mv O Max. Units Dropout Voltage I O 3 ma I O = 1 ma mv mv Quiescent Current I O 1 ma, V = V OUT 3V to 14V 4 1 µa Ripple Rejection f O = 12Hz 8 db Temperature Coefficient I O 1 ma, V = V OUT 3V to 14V ±.35 mv/ C Note 1: Absolute Maximum Ratings are limits beyond which damage to the device may occur. For guaranteed performance limits and associated test conditions, see the Electrical Characteristics tables. Note 2: See Circuit in Typical Applications. To ensure constant junction temperature, low duty cycle pulse testing is used. Note 3: Limits appearing in boldface type apply over the entire junction temperature range for operation. Limits appearing in normal type apply for T A = T J = 25 C. V V OUT Figure 1. SOT-89 Board Layout Advanced Monolithic Systems, Inc. Phone (925) Fax (925)

3 APPLICATION HTS Package Power Dissipation The package power dissipation is the level at which the thermal sensor monitoring the junction temperature is activated. The shuts down when the junction temperature exceeds the limit of 15 C. The junction temperature rises as the difference between the input power and output power increases. The mounting pad configuration on the PCB, the board material, as well as the ambient temperature affect the rate of temperature rise. The junction temperature will be low, even if the power dissipation is high, when the mounting of the device has good thermal conductivity. When mounted on the recommended mounting pad (figure1) the power dissipation for the SOT-89 package is 6mW. For operation above 25 C derate the power dissipation at 4.8mW/ C. To determine the power dissipation for shutdown when mounted, attach the device on the PCB and increase the input-to-output voltage until the thermal protection circuit is activated. Calculate the power dissipation of the device by subtracting the output voltage from the input voltage and multiply by the output current. The measurements should allow for the ambient temperature of the PCB. The value obtained from P D / (15 C - T A ) is the derating factor. The PCB mounting pad should provide maximum thermal conductivity in order to maintain low device temperatures. As a general rule, the lower the temperature, the better the reliability of the device. The thermal resistance when the device is mounted is equal to: T J = θ JA x P D T A The internal limit for junction temperature is 15 C. If the ambient temperature is 25 C, then: 15 C = θ JA x P D 25 C θ JA = 125 C/ P D A simple way to determine P D is to calculate V x I when the output is shorted. As the temperature rises, the input gradually will decrease. The P D value obtained when the thermal equilibrium is reached, is the value that should be used. The range of usable currents can be found from the graph in figure 2. P D D PD (mw) T ( C) Figure 2 Procedure: 1. Find P D. 2. P D1 is calculated as P D x (.8 -.9). 3. Plot P D1 against 25 C. 4. Connect P D1 to the point corresponding to the 15 C Take a vertical line from the maximum operating temperature (75 C) to the derating curve. 6. Read the value of P D at the point where the vertical line intersects the derating curve. This is the maximum power dissipation, D PD. The maximum operating current is: I OUT = (D PD / (V (MAX) - V O ) External Capacitors The series require an output capacitor for device stability. The value required depends on the application circuit and other factors. Because high frequency characteristics of electrolytic capacitors depend greatly on the type and even the manufacturer, the value of capacitance that works well with for one brand or type may not necessary be sufficient with an electrolytic of different origin. Sometimes actual bench testing will be the only means to determine the proper capacitor type and value. To obtain stability in all general applications a high quality 1µF aluminum electrolytic or a 47µF tantalum electrolytic can be used. A critical characteristic of the electrolytic capacitors is their performance over temperature. The is designed to operate to -4 C, but some electrolytics will freeze around -3 C therefore becoming ineffective. In such case the result is oscillation at the regulator output. For all application circuits where cold operation is necessary, the output capacitor must be rated to operate at the minimum temperature. In applications where the regulator junction temperature will never be lower than 25 C the output capacitor value can be reduced by a factor of two over the value required for the entire temperature range (47µF for a high quality aluminum or 22µF for a tantalum electrolytic capacitor). With higher output currents, the stability of decreases. Considering the fact that in many applications the is operated at only a few milliamps (or less) of output current, the output capacitor value can be reduced even further. For example, a circuit that is required to deliver a maximum of 1mA of output current from the regulator output will need an output capacitor of only half the value compared to the same regulator required to deliver the full output current of 1mA. As a general rule, with higher output voltages the value of the output capacitance decreases, since the internal loop gain is reduced. In order to determine the minimum value of the output capacitor, for an application circuit, the entire circuit including the capacitor should be bench tested at minimum operating temperatures and maximum operating currents. To maintain internal power dissipation and die heating to a minimum, the input voltage should be maintain at.6v above the output. Worst-case occurs just after input power is applied and before the die had the chance to heat up. After the minimum capacitance value has been found for the specific brand and type of electrolytic capacitor, the value should be doubled for actual use to cover for production variations both in the regulator and the capacitor. Advanced Monolithic Systems, Inc. Phone (925) Fax (925)

4 TYPICAL PERFORMANCE CHARACTERISTICS PUT OUTPUT DIFFERENTIAL (V) Dropout Voltage I O = 1mA.3.2 I O = 5mA.1 I O = 1mA JUNCTION TEMPERATURE ( C) PUT OUTPUT DIFFERENTIAL (V) Dropout Voltage OUTPUT VOLTAGE DEVIATION (mv) PUT VOLTAGE CHANGE (V) Line Transient Response 3 V = V OUT = 9V 2 C 2 = 1 µf TIME (µs) OUTPUT VOLTAGE DEVIATION (mv) LOAD CURRENT(mA) Load Transient Response C 2 = 1µF TIME (µs) OUTPUT CURRENT ( ma) Peak Output Current 3 25 T J = 25 C 2 T J = 85 C 15 T J = -4 C PUT VOLTAGE (V) 3 QUIESCENT CURRENT (ma) Quiescent Current 3 V = 14V QUIESCENT CURRENT (ma) Quiescent Current I O = 5mA 2 1 I O = ma TEMPERATURE ( C) QUIESCENT CURRENT ( ma) Quiescent Current I O = 1mA I O = 5mA I O = 1mA PUT VOLTAGE (V) RIPPLE REJECTION (db) Ripple Rejection I O = 1mA C2 = 1µF ALUM C2 = 1µF TANTALUM k 1k 1k 1M FREQUENCY (Hz) Advanced Monolithic Systems, Inc. Phone (925) Fax (925)

5 TYPICAL PERFORMANCE CHARACTERISTICS (Continued) RIPPLE REJECTION (db) Ripple Rejection F Q = 12Hz RIPPLE REJECTION (db) Ripple Rejection F Q = 12Hz EQUIVALENT SERIES RESISTANCE ( Ω) Output Capacitor ESR STABLE REGION C OUT = 1µF V O = 5V POWER DISSIPATION (W) Maximum Power Dissipation (TO-92).4" Lead Lenght from PC Board.125" Lead Lenght from PC Board AMBIENT TEMPERATURE ( C) POWER DISSIPATION (W) Maximum Power Dissipation (SOT-89) UNMOUNTED MOUNTED ON PCB AMBIENT TEMPERATURE ( C) Advanced Monolithic Systems, Inc. Phone (925) Fax (925)

6 TYPICAL APPLICATIONS Voltage Regulator Circuit Voltage Boost Circuit V UNREGULATED PUT C1*.1µF GND I Q C2** 1µF V OUT REGULATED OUTPUT 1µF V O 47µF V OUT I Q R *Required if regulator is located far from power supply filter. **C2 must be at least 1µF to maintain stability; it can be increased without bound to maintain regulation during transients and it should be located as close as possible to the regulator. This capacitor must be rated over the same operating temperature range like the regulator. The ESR of this capacitor is critical (see curve). V OUT = V O I Q R Current Boost Circuit Current Regulator Circuit 1 1µF GND 47µF V 1µF V O R 47µF I O I Q I O = (V O /R ) I Q Advanced Monolithic Systems, Inc. Phone (925) Fax (925)

7 PACKAGE DIMENSIONS inches (millimeters) unless otherwise noted. 3 LEAD TO-92 PLASTIC PACKAGE (N).6±.5 (1.524±.127) DIA.18±.5 (4.572±.127).18±.5 (4.572±.127).9 (2.286) NOM.6±.1 (1.524±.254).14±.1 (3.556±.127).5 (12.7) M.5 (1.27) MAX UNCONTROLLED LEAD DIMENSIONS 5 NOM 1 NOM.5±.5 (1.27±.127).16±.3 (.46±.76).15±.2 (.381±.51) N (TO-92 ) AMS DRW# SOT-89 PLASTIC PACKAGE (L) ( ) ( ) ( ) ( ) ( ) ( ) ( ) ( ).59 (1.5) BSC ( ) ( ) L (SOT-89 ) AMS DRW# (3.) BSC Advanced Monolithic Systems, Inc. Phone (925) Fax (925)

Advanced Monolithic Systems

Advanced Monolithic Systems FEATURES Fixed and Adjustable Versions Available Output Current up to Very Low Reverse Battery Protection Input-output Differential less than.6v Short Circuit Protection Internal